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In this study, we want to evaluate the efficacy of a preventive weight management training. We hypothesize that this training will reduce weight gain, pathological metabolic parameters and will increase drug compliance and subjective well-being.
69 schizophrenic patients were included in this study, in all patients olanzapine was newly initiated. They were randomly assigned to verum and control group. Patients in the verum group attended the training every second week for 24 weeks. Physical and chemical parameters where measured regularly, and also eating behaviour, physical activity, quality of life, mental state and psychosocial adaptation.
28 patients dropped out during the first 4 weeks of intervention. The data of the remaining 41 patients (verum group N=21, control group N=20) was analysed. During the intervention there was no significant difference between the groups regarding weight-gain. Both groups gained weight slightly (verum group 3.02±4.06kg, control group 2.80±4.84kg). Concerning triglycerides we found an interaction effect of time and group (F(1)=6.697, p=.025), the same was found on the second scale of the questionnaire for eating behaviour (FEV), which measures to what degree eating behaviour is disturbed (F(1)=8,381, p=.013) and on the social functioning scale of the SF-36 (F(2,38)=3,34, p=.032). Regarding glucose tolerance challenge, there was a significant group effect at the first time of measure after intake of the glucose-dilution (F(1)=9.15, p=.016). Our results do not support the hypothesis that the intervention has the desired effects on body weight, but it influenced positively other metabolic parameters, eating behaviour and social functioning.
: Human impulsivity is a complex multidimensional construct encompassing cognitive, emotional, and behavioral aspects. Previous animal studies have suggested that striatal dopamine receptors play a critical role in impulsivity. in this study, we investigated the relationship between self-reported cognitive impulsiveness and dopamine D2/3 receptor availability in striatal subdivisions in healthy subjects using high-resolution positron emission tomography (PET) with [11C]raclopride.
Twenty-one participants completed 3-Tesla magnetic resonance imaging and high-resolution PET scans with [11C]raclopride. The trait of impulsiveness was measured using the Barratt Impulsiveness Scale (BIS-11). Partial correlation analysis was performed between BIS-11 scores and D2/3 receptor availability in striatal subregions, controlling for the confounding effects of temperament characteristics that are conceptually or empirically related to dopamine, which were measured by the Temperament and Character Inventory.
The analysis revealed that the non-planning (p = 0.004) and attentional (p = 0.007) impulsiveness subscale scores on the BIS-11 had significant positive correlations with D2/3 receptor availability in the pre-commissural dorsal caudate. There was a tendency toward positive correlation between non-planning impulsiveness score and D2/3 receptor availability in the post-commissural caudate.
These results suggest that cognitive subtrait of impulsivity is associated with D2/3 receptor availability in the associative striatum that plays a critical role in cognitive processes involving attention to detail, judgment of alternative outcomes, and inhibitory control.
Several cross-sectional studies, but no prospective studies, have reported an association between an abnormal lipid profile and posttraumatic stress disorder (PTSD). We hypothesized that an abnormal lipid profile might predict risk for developing PTSD. In this prospective study, we analyzed data from 237 antidepressant-naïve severely injured patients who participated in the Tachikawa Cohort of Motor Vehicle Accident Study. High-density lipoprotein cholesterol (HDL-C) levels at baseline were significantly lower in patients with PTSD than those without PTSD at 6 months after motor vehicle accident (MVA) and were inversely associated with risk for PTSD. In contrast, triglycerides (TG) at baseline were significantly higher in patients with PTSD than in those without PTSD at 6 months post-MVA and were positively associated with risk for PTSD. There was no clear association between low-density lipoprotein cholesterol or total cholesterol and risk for PTSD. In conclusion, low HDL-C and high TG may be risk factors for PTSD. Determining lipid profiles might help identify those at risk for PTSD after experiencing trauma.
Both trauma-focused cognitive behaviour therapy and antidepressant medication are regarded as the first line treatments for post-traumatic stress disorder (PTSD). However, little is known about sequential or combined efficacy of these two different treatment options. This prospective study examined the add-on efficacy of eye movement desensitization and reprocessing (EMDR) therapy among adult civilians with PTSD who continued to be symptomatic after antidepressant treatment.
Adult patients with PTSD at a specialized trauma clinic who received treatment doses of antidepressants for more than 12 weeks were recruited; definition of symptomatic PTSD was a total score > 40 on the Clinician-administered PTSD Scale (CAPS). The CAPS and the global improvement from Clinical Global Impression (CGI) were rated prior to EMDR, after termination and six months follow-up.
A total of 15 patients underwent an average of six sessions of EMDR and 7 (47%) of 15 no longer met the criteria for PTSD and 10 (67%) were given status of very much or much improved. The CAPS scores and significantly decreased after EMDR therapy (paired t = 7.38, df = 14, P < 0.0001).
These results indicate that EMDR or trauma-focused CBT can be successfully added to those who failed to improve after initial pharmacotherapy for PTSD. Further studies are needed to explore the best sequence or components of therapies in the treatment of PTSD.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
Heat shock proteins (HSPs) consist of highly preserved stress proteins that are expressed in response to stress. Two studies were carried out to investigate whether HSP genes in hair follicles from beef calves can be suggested as indicators of heat stress (HS). In study 1, hair follicles were harvested from three male Hanwoo calves (aged 172.2 ± 7.20 days) on six dates over the period of 10 April to 9 August 2017. These days provided varying temperature–humidity indices (THIs). In study 2, 16 Hanwoo male calves (aged 169.6 ± 4.60 days, with a BW of 136.9 ± 6.23 kg) were maintained (4 calves per experiment) in environmentally controlled chambers. A completely randomized design with a 2 × 4 factorial arrangement involving two periods (thermoneutral: TN; HS) and four THI treatment groups (threshold: THI = 68 to 70; mild: THI = 74 to 76; moderate THI = 81 to 83; severe: THI = 88 to 90). The calves in the different group were subjected to ambient temperature (22°C) for 7 days (TN) and subsequently to the temperature and humidity corresponding to the target THI level for 21 days (HS). Every three days (at 1400 h) during both the TN and HS periods, the heart rate (HR) and rectal temperature (RT) of each individual were measured, and hair follicles were subsequently collected from the tails of each individual. In study 1, the high variation (P < 0.0001) in THI indicated that the external environment influenced the HS to different extents. The expression levels of the HSP70 and HSP90 genes at the high-THI level were higher (P = 0.0120, P = 0.0002) than those at the low-THI level. In study 2, no differences in the THI (P = 0.2638), HR (P = 0.2181) or RT (P = 0.3846) were found among the groups during the TN period, whereas differences in these indices (P < 0.0001, P < 0.0001 and P < 0.0001, respectively) were observed during the HS period. The expression levels of the HSP70 (P = 0.0010, moderate; P = 0.0065, severe) and HSP90 (P = 0.0040, severe) genes were increased after rapid exposure to heat-stress conditions (moderate and severe levels). We conclude that HSP gene expression in hair follicles provides precise and accurate data for evaluating HS and can be considered a novel indicator of HS in Hanwoo calves maintained in both external and climatic chambers.
To investigate the association between parity and the risk of incident dementia in women.
We pooled baseline and follow-up data for community-dwelling women aged 60 or older from six population-based, prospective cohort studies from four European and two Asian countries. We investigated the association between parity and incident dementia using Cox proportional hazards regression models adjusted for age, educational level, hypertension, diabetes mellitus and cohort, with additional analysis by dementia subtype (Alzheimer dementia (AD) and non-Alzheimer dementia (NAD)).
Of 9756 women dementia-free at baseline, 7010 completed one or more follow-up assessments. The mean follow-up duration was 5.4 ± 3.1 years and dementia developed in 550 participants. The number of parities was associated with the risk of incident dementia (hazard ratio (HR) = 1.07, 95% confidence interval (CI) = 1.02–1.13). Grand multiparity (five or more parities) increased the risk of dementia by 30% compared to 1–4 parities (HR = 1.30, 95% CI = 1.02–1.67). The risk of NAD increased by 12% for every parity (HR = 1.12, 95% CI = 1.02–1.23) and by 60% for grand multiparity (HR = 1.60, 95% CI = 1.00–2.55), but the risk of AD was not significantly associated with parity.
Grand multiparity is a significant risk factor for dementia in women. This may have particularly important implications for women in low and middle-income countries where the fertility rate and prevalence of grand multiparity are high.
We aimed to investigate the heterogeneity of seasonal suicide patterns among multiple geographically, demographically and socioeconomically diverse populations.
Weekly time-series data of suicide counts for 354 communities in 12 countries during 1986–2016 were analysed. Two-stage analysis was performed. In the first stage, a generalised linear model, including cyclic splines, was used to estimate seasonal patterns of suicide for each community. In the second stage, the community-specific seasonal patterns were combined for each country using meta-regression. In addition, the community-specific seasonal patterns were regressed onto community-level socioeconomic, demographic and environmental indicators using meta-regression.
We observed seasonal patterns in suicide, with the counts peaking in spring and declining to a trough in winter in most of the countries. However, the shape of seasonal patterns varied among countries from bimodal to unimodal seasonality. The amplitude of seasonal patterns (i.e. the peak/trough relative risk) also varied from 1.47 (95% confidence interval [CI]: 1.33–1.62) to 1.05 (95% CI: 1.01–1.1) among 12 countries. The subgroup difference in the seasonal pattern also varied over countries. In some countries, larger amplitude was shown for females and for the elderly population (≥65 years of age) than for males and for younger people, respectively. The subperiod difference also varied; some countries showed increasing seasonality while others showed a decrease or little change. Finally, the amplitude was larger for communities with colder climates, higher proportions of elderly people and lower unemployment rates (p-values < 0.05).
Despite the common features of a spring peak and a winter trough, seasonal suicide patterns were largely heterogeneous in shape, amplitude, subgroup differences and temporal changes among different populations, as influenced by climate, demographic and socioeconomic conditions. Our findings may help elucidate the underlying mechanisms of seasonal suicide patterns and aid in improving the design of population-specific suicide prevention programmes based on these patterns.
To analyse how the auditory brainstem response changes in patients with sudden sensorineural hearing loss.
Data were collected via retrospective medical chart review.
Forty-three patients were included in this study. The mean latency of auditory brainstem response wave 1 was significantly longer for the affected side than for the unaffected side (p = 0.003). The mean latency of auditory brainstem response wave 1 was significantly shorter, and the mean amplitude of auditory brainstem response wave 1 was significantly larger, in the good response group compared to the poor response group. In forward conditional logistic regression analysis, auditory brainstem response wave 1 latency was an independent predictor of a good response (odds ratio = 34.37, 95 per cent confidence interval = 1.56–757.15, p = 0.025).
In patients with sudden sensorineural hearing loss, the latency of wave 1 of the auditory brainstem response was significantly increased and was related to prognosis.
Item 9 of the Patient Health Questionnaire-9 (PHQ-9) queries about thoughts of death and self-harm, but not suicidality. Although it is sometimes used to assess suicide risk, most positive responses are not associated with suicidality. The PHQ-8, which omits Item 9, is thus increasingly used in research. We assessed equivalency of total score correlations and the diagnostic accuracy to detect major depression of the PHQ-8 and PHQ-9.
We conducted an individual patient data meta-analysis. We fit bivariate random-effects models to assess diagnostic accuracy.
16 742 participants (2097 major depression cases) from 54 studies were included. The correlation between PHQ-8 and PHQ-9 scores was 0.996 (95% confidence interval 0.996 to 0.996). The standard cutoff score of 10 for the PHQ-9 maximized sensitivity + specificity for the PHQ-8 among studies that used a semi-structured diagnostic interview reference standard (N = 27). At cutoff 10, the PHQ-8 was less sensitive by 0.02 (−0.06 to 0.00) and more specific by 0.01 (0.00 to 0.01) among those studies (N = 27), with similar results for studies that used other types of interviews (N = 27). For all 54 primary studies combined, across all cutoffs, the PHQ-8 was less sensitive than the PHQ-9 by 0.00 to 0.05 (0.03 at cutoff 10), and specificity was within 0.01 for all cutoffs (0.00 to 0.01).
PHQ-8 and PHQ-9 total scores were similar. Sensitivity may be minimally reduced with the PHQ-8, but specificity is similar.
Abnormal Ca homeostasis has been associated with impaired glucose metabolism. However, the epidemiological evidence is controversial. We aimed to assess the association between circulating Ca levels and the risk of type 2 diabetes mellitus (T2DM) or abnormal glucose homeostasis through conducting a systematic review and meta-analysis. Eligible studies were identified by searching electronic database (PubMed, Embase and Google Scholar) and related references with de novo results from primary studies up to December 2018. A random-effects meta-analysis was performed to estimate the weighted relative risks (RR) and 95 % CI for the associations. The search yielded twenty eligible publications with eight cohort studies identified for the meta-analysis, which included a total of 89 165 participants. Comparing the highest with the lowest category of albumin-adjusted serum Ca, the pooled RR was 1·14 (95 % CI 1·05, 1·24) for T2DM (n 51 489). Similarly, serum total Ca was associated with incident T2DM (RR 1·25; 95 % CI 1·10, 1·42) (n 64 502). Additionally, the adjusted RR for 1 mg/dl increments in albumin-adjusted serum Ca or serum total Ca levels was 1·16 (95 % CI 1·07, 1·27) and 1·19 (95 % CI 1·11, 1·28), respectively. The observed associations remained with the inclusion of a cohort study with ionised Ca as the exposure. However, data pooled from neither case–control (n 4) nor cross-sectional (n 8) studies manifested a significant correlation between circulating Ca and glucose homeostasis. In conclusion, accumulated data from the cohort studies suggest that higher circulating Ca levels are associated with an augmented risk of T2DM.
To determine the factors related to multiple ventilation tube insertions in children with otitis media with effusion.
A retrospective review was performed of 126 ears of 81 children aged less than 12 years who had undergone insertion of a Paparella type 1 ventilation tube for the first time between August 2012 and March 2018.
Mean age at the first operation was 4.0 ± 2.2 years, and the mean duration of otitis media with effusion before the first ventilation tube insertion was 5.4 ± 4.5 months. Among 126 ears, 80 (63.5 per cent) had a single ventilation tube insertion and 46 (36.5 per cent) had multiple insertions. On multivariate logistic regression, tympanic membrane retraction, serous middle-ear discharge, and early recurrence of otitis media with effusion were independent predictive factors of multiple ventilation tube insertions.
Tympanic membrane retraction, serous middle-ear discharge, and early recurrence of otitis media with effusion after the first tube extrusion are associated with multiple ventilation tube insertions.
Although maternal pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) are related to fetal growth, there is a paucity of data regarding how offspring sex affects the relationship between maternal BMI in underweight mothers (pre-pregnancy BMI <18.5 kg/m2) and size for gestational age at birth. The aim of this study was to investigate the effect of offspring sex on the relationships among maternal pre-pregnancy BMI, GWG and size for gestational age at birth in Japanese underweight mothers. Records of women with full-term pregnancies who underwent perinatal care at Kawasaki Municipal Hospital (Kawasaki, Japan) between January 2013 and December 2017 were retrospectively reviewed. The study cohort included underweight (n=566) and normal-weight women (18.5 kg/m2⩽pre-pregnancy BMI<25 kg/m2; n=2671). The incidence of small for gestational age (SGA) births in the underweight group was significantly higher than that in the normal-weight group (P<0.01). Additionally, SGA incidence in the underweight group was significantly higher than that in the normal-weight group (P<0.01) in female, but not male (P=0.30) neonates. In the women with female neonates, pre-pregnancy underweight was associated with a significantly increased probability of SGA (odds ratio [OR]: 1.80; P<0.01), but inadequate GWG was not (OR: 1.38; P=0.11). In contrast, in women with male neonates, inadequate GWG was associated with a significantly increased probability of SGA (OR: 1.53; P=0.03), but not with pre-pregnancy underweight (OR: 1.30; P=0.10). In conclusion, the present results suggest that pre-pregnancy underweight is associated with SGA in female offspring but not in male offspring.
Given the challenges in accurately identifying unexposed controls in case–control studies of diarrhoea, we examined diarrhoea incidence, subclinical enteric infections and growth stunting within a reference population in the Global Enteric Multicenter Study, Kenya site. Within ‘control’ children (0–59 months old without diarrhoea in the 7 days before enrolment, n = 2384), we examined surveys at enrolment and 60-day follow-up, stool at enrolment and a 14-day post-enrolment memory aid for diarrhoea incidence. At enrolment, 19% of controls had ⩾1 enteric pathogen associated with moderate-to-severe diarrhoea (‘MSD pathogens’) in stool; following enrolment, many reported diarrhoea (27% in 7 days, 39% in 14 days). Controls with and without reported diarrhoea had similar carriage of MSD pathogens at enrolment; however, controls reporting diarrhoea were more likely to report visiting a health facility for diarrhoea (27% vs. 7%) or fever (23% vs. 16%) at follow-up than controls without diarrhoea. Odds of stunting differed by both MSD and ‘any’ (including non-MSD pathogens) enteric pathogen carriage, but not diarrhoea, suggesting control classification may warrant modification when assessing long-term outcomes. High diarrhoea incidence following enrolment and prevalent carriage of enteric pathogens have implications for sequelae associated with subclinical enteric infections and for design and interpretation of case–control studies examining diarrhoea.
To investigate whether amnestic mild cognitive impairment (aMCI) identified with visual memory tests conveys an increased risk of Alzheimer’s disease (risk-AD) and if the risk-AD differs from that associated with aMCI based on verbal memory tests.
4,771 participants aged 70.76 (SD = 6.74, 45.4% females) from five community-based studies, each a member of the international COSMIC consortium and from a different country, were classified as having normal cognition (NC) or one of visual, verbal, or combined (visual and verbal) aMCI using international criteria and followed for an average of 2.48 years. Hazard ratios (HR) and individual patient data (IPD) meta-analysis analyzed the risk-AD with age, sex, education, single/multiple domain aMCI, and Mini-Mental State Examination (MMSE) scores as covariates.
All aMCI groups (n = 760) had a greater risk-AD than NC (n = 4,011; HR range = 3.66 – 9.25). The risk-AD was not different between visual (n = 208, 17 converters) and verbal aMCI (n = 449, 29 converters, HR = 1.70, 95%CI: 0.88, 3.27, p = 0.111). Combined aMCI (n = 103, 12 converters, HR = 2.34, 95%CI: 1.13, 4.84, p = 0.023) had a higher risk-AD than verbal aMCI. Age and MMSE scores were related to the risk-AD. The IPD meta-analyses replicated these results, though with slightly lower HR estimates (HR range = 3.68, 7.43) for aMCI vs. NC.
Although verbal aMCI was most common, a significant proportion of participants had visual-only or combined visual and verbal aMCI. Compared with verbal aMCI, the risk-AD was the same for visual aMCI and higher for combined aMCI. Our results highlight the importance of including both verbal and visual memory tests in neuropsychological assessments to more reliably identify aMCI.
To evaluate the relationships between maternal fish consumption and pregnancy outcomes in a large, population-based sample of women in the USA.
We collected average fish consumption prior to pregnancy using a modified version of the semi-quantitative Willett FFQ. We estimated adjusted OR (aOR) and 95 % CI for associations between different levels of fish consumption and preterm birth (<37 weeks), early preterm birth (<32 and <35 weeks) and small-for-gestational-age infants (SGA; <10th percentile).
The National Birth Defects Prevention Study (NBDPS).
Control mother–infant pairs with estimated delivery dates between 1997 and 2011 (n 10 919).
No significant associations were observed between fish consumption and preterm birth or early preterm birth (aOR = 0·7–1·0 and 0·7–0·9, respectively). The odds of having an SGA infant were elevated (aOR = 2·1; 95 % CI 1·2, 3·4) among women with daily fish consumption compared with women consuming fish less than once per month. No associations were observed between other levels of fish consumption and SGA (aOR = 0·8–1·0).
High intake of fish was associated with twofold higher odds of having an SGA infant, while moderate fish consumption prior to pregnancy was not associated with preterm or SGA. Our study, like many other studies in this area, lacked information regarding preparation methods and the specific types of fish consumed. Future studies should incorporate information on nutrient and contaminant contents, preparation methods and biomarkers to assess these relationships.
Background: To determine whether exosomal microRNAs (miRNAs) in CSF of patients with FTD can serve as diagnostic biomarkers, we assessed miRNA expression in the Genetic FTD Initiative (GENFI) cohort and in sporadic FTD. Methods: GENFI participants were either carriers of a pathogenic mutation or at risk of carrying a mutation because a first-degree relative was a symptomatic mutation carrier. Exosomes were isolated from CSF of 23 -pre-symptomatic and 15 symptomatic mutation carriers, and 11 healthy non-mutation carriers. Expression of miRNAs was measured using qPCR arrays. MiRNAs differentially expressed in symptomatic compared to pre-symptomatic mutation carriers were evaluated in 17 patients with sporadic FTD, 13 patients with sporadic Alzheimer’s disease (AD), and 10 healthy controls (HCs). Results: In the GENFI cohort, miR-204-5p and miR-632 were significantly decreased in symptomatic compared to pre-symptomatic mutation carriers. Decrease of miR-204-5p and miR-632 revealed receiver operator characteristics with an area of 0.89 [90% CI: 0.79-0.98] and 0.81 [90% CI: 0.68-0.93], and when combined an area of 0.93 [90% CI: 0.87-0.99]. In sporadic FTD, only miR-632 was significantly decreased compared to sporadic AD and HCs. Decrease of miR-632 revealed an area of 0.89 [90% CI: 0.80-0.98]. Conclusions: Exosomal miR-204-5p and miR-632 have potential as diagnostic biomarkers for genetic FTD and miR-632 also for sporadic FTD.
Different diagnostic interviews are used as reference standards for major depression classification in research. Semi-structured interviews involve clinical judgement, whereas fully structured interviews are completely scripted. The Mini International Neuropsychiatric Interview (MINI), a brief fully structured interview, is also sometimes used. It is not known whether interview method is associated with probability of major depression classification.
To evaluate the association between interview method and odds of major depression classification, controlling for depressive symptom scores and participant characteristics.
Data collected for an individual participant data meta-analysis of Patient Health Questionnaire-9 (PHQ-9) diagnostic accuracy were analysed and binomial generalised linear mixed models were fit.
A total of 17 158 participants (2287 with major depression) from 57 primary studies were analysed. Among fully structured interviews, odds of major depression were higher for the MINI compared with the Composite International Diagnostic Interview (CIDI) (odds ratio (OR) = 2.10; 95% CI = 1.15–3.87). Compared with semi-structured interviews, fully structured interviews (MINI excluded) were non-significantly more likely to classify participants with low-level depressive symptoms (PHQ-9 scores ≤6) as having major depression (OR = 3.13; 95% CI = 0.98–10.00), similarly likely for moderate-level symptoms (PHQ-9 scores 7–15) (OR = 0.96; 95% CI = 0.56–1.66) and significantly less likely for high-level symptoms (PHQ-9 scores ≥16) (OR = 0.50; 95% CI = 0.26–0.97).
The MINI may identify more people as depressed than the CIDI, and semi-structured and fully structured interviews may not be interchangeable methods, but these results should be replicated.
Declaration of interest
Drs Jetté and Patten declare that they received a grant, outside the submitted work, from the Hotchkiss Brain Institute, which was jointly funded by the Institute and Pfizer. Pfizer was the original sponsor of the development of the PHQ-9, which is now in the public domain. Dr Chan is a steering committee member or consultant of Astra Zeneca, Bayer, Lilly, MSD and Pfizer. She has received sponsorships and honorarium for giving lectures and providing consultancy and her affiliated institution has received research grants from these companies. Dr Hegerl declares that within the past 3 years, he was an advisory board member for Lundbeck, Servier and Otsuka Pharma; a consultant for Bayer Pharma; and a speaker for Medice Arzneimittel, Novartis, and Roche Pharma, all outside the submitted work. Dr Inagaki declares that he has received grants from Novartis Pharma, lecture fees from Pfizer, Mochida, Shionogi, Sumitomo Dainippon Pharma, Daiichi-Sankyo, Meiji Seika and Takeda, and royalties from Nippon Hyoron Sha, Nanzando, Seiwa Shoten, Igaku-shoin and Technomics, all outside of the submitted work. Dr Yamada reports personal fees from Meiji Seika Pharma Co., Ltd., MSD K.K., Asahi Kasei Pharma Corporation, Seishin Shobo, Seiwa Shoten Co., Ltd., Igaku-shoin Ltd., Chugai Igakusha and Sentan Igakusha, all outside the submitted work. All other authors declare no competing interests. No funder had any role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review or approval of the manuscript; and decision to submit the manuscript for publication.
Introduction: The cricothyroid membrane is used as a landmark for emergent surgical airway access. Ultrasound identification of the cricothyroid membrane is more accurate than landmarking by palpation. The objective of this study was to determine whether head of bed elevation affects the position of the cricothyroid membrane as identified by ultrasound. Methods: This was a prospective, observational study on a convenience sample of adult patients presenting to the emergency department. Participants underwent ultrasound scans by trained physicians at 0, 30 and 90 degrees head of bed elevation to identify the cricothyroid membrane. The cricothyroid membrane position identified at 0 degrees was used as a reference, and the change in position of the external landmark of the cricothyroid membrane with the patient at 30 and 90 degrees was measured. Additionally, the patients gender, age, body mass index (BMI) and Mallampati score were recorded for comparison. Linear mixed effects models with 95% confidence intervals were used to determine the effect of head of bed elevation, age, BMI and Mallampati score on the differences between measured distances. Results: One hundred and two patients were enrolled in the study. The average change in position from reference was statistically significant for both 30 degrees [2.72±0.77mm (p<0.01)] and 90 degrees [4.23±0.77mm (p<0.01)] head of bed elevation. The adjusted linear mixed effects model showed age greater than 70, BMI over 30 and higher Mallampati score were associated with greater change in distance between cricothyroid membrane landmarks. Conclusion: There was a statistically significant difference in the position of the cricothyroid membrane comparing 0 degrees to 30 and 90 degrees head of bed elevation. However, the relatively small differences suggest that this finding is not clinically relevant. Further study is required to evaluate if these differences impact the actual successful performance of cricothyrotomy.